一个菜鸟的oracle之路----------三(三)
from emp_xxx
where deptno=20);
//该题目也很经典，是我自己做出来的O(∩_∩)O哈哈~
案例19 列出员工的名字和职位，这些员工所在的部门的平均薪水大于5000元
[sql]
select ename,job
from emp_xxx;
//首先查询出部门平均薪水大于5000元的部门
[sql]
select deptno
from emp_xxx
group by deptno
having avg(nvl(salary,0))>5000;
//汇总以后的结果为
[sql]
select ename,job
from emp_xxx
where deptno in (select deptno
from emp_xxx
group by deptno
having avg(nvl(salary,0))>2000);
//该示例也非常经典，综合考察了 group by having avg nvl 子查询等知识